Base for a portable building



FIG. 1 is a perspective view of a base for a portable building showingour new design;

FIG. 2 is another perspective view showing the bottom thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a left side elevational view thereof; and,

FIG. 8 is a right side elevational view thereof.

The ornamental design for a base for a portable building, as shown anddescribed.